On-off plunger



FIG. 1 is a perspective view of the plunger shown in one environment;

FIG. 2 is a perspective view of the plunger:

FIG. 3 is a front elevation view of the plunger, with the rear elevation view being identical to the front elevation view:

FIG. 4 is a left elevation view of the plunger, with the right elevation view being identical to the left elevation view;

FIG. 5 is a top plan view of the plunger; and,

FIG. 6 is a bottom plan view of the plunger.

The broken line showing an O-ring seat in FIGS. 2, 3, and 4 is for illustrative purposes only and forms no part of the claimed design. Likewise. the broken line showing a pump housing in FIG. 1 is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for an on-off plunger, as shown and described. 